Process for transferring a gelatin image bearing film



March 2, 1954 A. w. GRUMBINE ET AL 2,671,020

PROCESS FOR TRANSFERRING A GELATIN IMAGE BEARING FILM Filed Sept. 14, 1949 Film base Blue record emulsion Watersoluble or swellable adhesive Green record emulsion Red record emulsion Film base (a) Expose Aand B in contact i l Separate AandB (c) Soak A in aqueous solution pH below 4.5

containing anionic surface active wetting agent-press layer 4 into contact with layer 8 of film C.

Gelatin Film Base Blank Film-C (d) 'Strip layer 4 from film A (e) Develop and fix before step (c) or Film base Film base INVENTOR Arthur WiIIiam Grumbine Jacob Quentin Umberger BYGWZZMW ATTORNEY Patented Mar. 2, i954 PROCESS FOR TRANSFERRING A GELATIN IMAGE BEARING FILM Arthur William Grumbine, Berlin, and Jacob Quentin Umberger, Holmdel, N. J assignors to E...I. du Pontde Nemours & Company, =Wilmington, Del., a corporation of Delaware Application September 14, 1949, Serial No. 115,772

10 Claims. (01. 95-2) This invention relates to photography and more particularly to a process of increasing the adherence of gelatin layers to eachrother. Still more particularly it relates to a process of transfer'ring a gelatino silver halide or silver imagebearinglayer to a gelatin-blank film, improving the adherence between such layers, and to processing solutions therefor.

An object of this invention is to improve the anchorage between gelatin-blank films and transferred gelatino silver halides or silver image-bearing layers. Another object is to improve a process of transferring a gelatin silver halide or silver image-bearing layer from a stripping film to a gelatin-blank film. A further object isto provide a simple and economical process for improving such anchorage. Still other objects will be apparent from the follow ing description of the invention.

Various types of stripping films are known which consist of a gelatino silver'halide layer which is releasably joined to a support such as a cellulose derivative,.superpolymer, e. g., polyvinyl acetal or nylonfilm, baryta-coated paper, glass, etc., or to another gelatino silver halide emulsion'layer or other layer on such a support bymeans'of a water-soluble or other adhesive. Th'eouter. gelatin or image-bearing layer is transferred'either before or after development to a gelatin-blank film. This film consists of a film base which has a thin gelatin layer often containing an acid, e. g., acetic, lactic, citric, etc.,

coated on it. The two gelatin layers of the re spective films areppressed into contact and the image-bearing layer which adheres to the gelatin blank isvstripped from its original sup- Port. The washing water generally weakens or dissolves the stripping layer which allows the stripping action to take place. The normal washing operationis frequenly not sufficient to loosen'the bond between the layers so a special aqueous transferring bath or treatment is used with films to be transferred after development. The processing can be interrupted after normal developmentfixation and washing and the film dried for use at a later time.

It has been found that the anchorage between the gelatin surfaces of the gelatin-blank and the gelatin image-bearing layer of the stripping film can be markedly improved by adding to the aqueous transferring bath an anionic watersolublesurface active wetting agent and adjust ing' the pH'to 4.5 or below, e. g., 1.0 to 4.5. The improved anchorage is surprisingsinoe wetting agents produoe a slippery or slimy surface which efficient process is obtained. Each light-sensi tive stratum containing latent images maybe given individual treatment thus giving the-pho tographic technician greater latitude in the op-. eration whereas if stripping is done after de velopment individual control ofeach latent image-bearing layer cannot be accomplished.

The stripping films which can be used mac cordance with the procedures of this'invention. may contain variouswater-soluble, water-insolu- Thus, theyble or water-swellable adhesives. may be composed of water-soluble cellulose. ethers, e. g., methyl cellulose, ethyl cellulose, cellulose glycolic acid and its water-soluble salts such as alkali metal, ammonium and amine salts, water-soluble starch derivatives, e. g.-, starch glycolic acid and its water-soluble. alkali metal.

ammonium and amine salts; polyvinyl-alcohol, etc. stripping films disclosed in Jennings U.- S. Patent 2,462,503. constitute the front film (A) of a bipack. The

stripping layer which is disposed between two gelatino silver halide emulsion layers is composed essentially of -a water-soluble macromolecular acetal of a hydroxyl polymer containing a plurality of recurring intralinear or vinyl alcohol units. These acetals are watersoluble by virtue of the fact that the hydrocarbon nucleus which is linked to the hydroxyl poly-- mer nucleus through an acetal linkage has a hy- 1 drogen atom substituted by a group taken from the class consisting of --COOX and -SO3X,

groups wherein X is a hydrogen atom or a water soluble cation, e. g., alkali metal, ammonium or' an amine salt group.

The sodium salt of the o-benzaldehyde sulfonic acid acetal of polyvinyl alcohol constitutes the preferred stripping layer of the films'disclosed in U. S. Patent 2,462,503. The alkali metal salts of the aliphatic sulfo-aldehydes of'the formula HSOMCHZMCHO, where n is 2 to 10,'e. g., beta-sulfopropionaldehyde, aliphatic carboxyaldehydes of the formula 'HOOC(CH2 )'nCHO, where n is 2 to 10, e. g., beta formylpropionic" benzaldehydeparasulfonic acid, teraphthalaldehydic acid, p (beta-formy-lethyl) acid;

2 reduce the anchorage be- The preferred wetting agentsare' The process is particularly useful with the- The stripping films of that patent benzoic acid and o-carboxymethoxybenzaldehyde are also described in the aforesaid application and are beneficially employed in accordance with this invention.

In the schematic drawing, which constitutes a part of this specification, there is shown the front film A of a bipack consisting of film base I, blue record emulsion 2, stripping layer 3 composed of the aforementioned water-soluble or water-swellable adhesive and green record emulslon 4; the rear film of the bipack consisting of base 5 and red record emulsion 0; and a gelatin blank film consisting of film base 1 and gelatin layer 8. The drawing also contains legends and arrows to indicate the exposing, developing, soaking, and transferring steps. In addition, there is shown the resulting three developed green, blue and red records 4', 2' and 6' on their respective bases 1, l and 5.

The invention will be further illustrated but is not intended to be limited by the following examples:

EXAIVIPLE I A cellulose nitrate film base having a thin gelatin coating was coated to a weight of 52 mg. silver halide per sq. dec. with a gelatino-silver lodobromide emulsion which had admixed therewith 50% by weight based on the silver salt of yellow colloidal silver (0.7% silver dispersed in aqueous gelatin solution). After drying, a solution containing 50 grams of a polyvinyl acetal per 1,000 grams of 20% ethanol, obtained by heating the mixture 45 minutes at 125 F., and cooling to 90 F. was coated to form a layer 0.0001 inch thick. This acetal was prepared by stirring a mixture of 44 parts of 100% hydrolyzed polyvinyl acetate (medium viscosity molecular weight 15,000 to 20,000), 40 parts of glacial acetic acid, 40 parts of sodium o-benzaldehyde sulfonatemonohydrate, and 6 parts of 85% phosphoric acid at 75 to 80 C. for one to two hours. The product is then precipitated by the addition of 1,000 parts of acetone, and dried to give 75 parts of a white solid. Next, a gelatino-silver iodobromide emulsion containing 1,1-diethyl 2,2'-cyanine iodide as an ortho-sensitizing dye was coated on the acetal layer to a weight of 48 mg. silver halide per sq. dec. A gelatin solution containing 450 grams of gelatin per 14,400 grams of water was coated in like manner to form a thin anti-abrasion layer. This film element constitutes the front film (A) of a bipack. It is slit and perforated to form a motion picture film.

A similar film base was coated with a thin gelatin substratum and dried. A gelatino-silver iodobromide emulsion containing as a green blind sensitizing dye 1,1 diethyl -2,4- carbocyanine iodide was coated on the gelatin substratum. It constitutes the rear film of a bipack and is slit and perforated in like manner to form a motion picture film.

The front film was processed as follows:

(1) Developed for 10 minutes at 68 F. in a developer made by admixing the following components:

Water (125 F. or 53 C.) cc 500.0 N-p-methylaminophenol sulfate grams 3.0 Sodium sulfite, desiccated do 45.0 Hydroquinone do 12.0 Sodium carbonate, desiccated do 67.5 Potassium bromide do 1.9 Cold water added to make 1.0 liter.

4 (2) Rinsed for 30 seconds at 68 F. in a solution made by admixing the following components:

Sodium sulfate, desiccated grams 100.0 Borax ..do 10.0 Water added to make 1.0 liter.

(3) Fixed for 8 minutes at 68 F. in a fixer made by admixing the following components:

Sodium thiosulfate grams 240.0 Sodium sulfite, desiccated do 15.0 Acetic acid, 28% pure cc 48.0 Boric acid, crystals grams 7.5 Potassium alum do 15.0

Water to 1.0 liter.

(4) Soaked for 2 minutes at 70 F. with agitation in a solution made by admixing the following components:

Sodium dodecyl sulfate, dry grams 1 to 10 Water (90 F.) cc Ethyl alcohol (95% by Weight) cc 600 (5) The outer layer of the film (A) was then pressed into intimate contact with a second registered or unregistered support comprising a transparent film base coated with a gelatin layer having a gelatin coating weight of about '70 mg. per sq. dec. Hereinafter this gelatin-coated transparent film will be referred to as a gel blank. The gelatin layer was coated from a 6% solution of gelatin containing saponin as a wetting agent and also containing 10 to 20 cc. lactic acid per liter of gelatin solution.

(6) After the film (A) was in contact with the gel-blank film for about 2 minutes, the films were separated with the result that the outer emulsion transferred to the gel-blank. The anchor age between the gelatin layers of the two films was excellent and better than that resulting when the solution was free of wetting agent.

EXAMPLE II A film element similar to that described in Example I was exposed and processed by steps 1, 2 and 3 of that example. The film was then soaked for 2 minutes at 68 F. with agitation in a solution made by mixing the following components:

Sodium dodecyl sulfate, dry grams.. 50 Water, F. to make 1 liter.

EXAILFLPLE III Samples of a film like that of Example I were exposed, processed, transferred and stripped after the manner described in said example except that the following transferring baths were substituted for the bath described in step 4.

Bath A Sodium dodecyl sulfate, dry grams 50.0

Citric acid, U. S. P. granulated do 15.0

Water to make 1.0 liter.

- (Jone. sulfuric acid to lower pH to 2.0: 0.1

a Bath. Be

C'rtriacidfUl SI'R. granlllatd'l dnl 15m Waterfto make li'Orliter. Disodium monohydrogeni phosphate? added 6,; Atmatemtime theadriedmlrm(Alawasgsoakede x70 isecaat 73ff'El-e in ithG'L-ISOlUfiOIIZIlrOduCedSib mixing equal volumes of baths E and F of amplezl'lliandipressedzinto:intimatecontact iwith i ax geleblankz similar rim; that of. Example: I butw M with aecoatin-g-trweightzof.150$mg...gelatin1ner" to lelse p o 1 square decimeters Bath 0 After a..contact time of only 30,seconds,,the Sodium dodecyl Sulfate, dry filfns were. separatedlwitli resultant; emulsion, Citric acid," U. s; P? granulatedi do: 1510 transfer as m'EXamPIH- Waterto:makei'1;01iter-: Disodium" monohydrogem phosphate added to "raiSemI-Itcr 01 051" V BaflIILDr Sodium'dodecyl-suliate: dry g; 50 .0 Citritza'cidfU. Pfgranulat'edi g; :0

Waterto ma-ke'1=:0*liter:

Disodiurrr m'onol'iydrogerr phosphate added" to. raise pH to 4.5:.

Itewas found, that if the. pH oft. Bathe D was raised .toteitherf 7-01 1ODWithammon-ium hydmXP- ide,.-.the:-ancho1=agewasquitezpoora Bath Monosodium dihydrogenphosphate mono.-

hydrate. g 5:0

Water to make 1.0 liter.

85%,,ph0sphoric. acid-laddecl-ito lower pHsto 2.0

Bath F'-' Sodium: tetralim sul'fona-te g 50.0 Monosodium dihydrogen phosphate-e mono:

hydrate "gt-.. 5.0.: Citric: acid;.U. S;--P: g 16.0. Water tormakerl-zO liter.

85 phosphoriceaddedzto lower: pH to- 2:0

0915410 lfiicarb'on'atomfi'and' distmdwateptb Example-ISLwase-processedlaszdescribediinithata 250 cc. of solution. This solutlomhad a-pI-Fof 2.05.

Bath-I Eoun' co 859/272 phosphoric-:acid pluse35tcozof a 30%eaqueousmixtu reeofi'sodium alkane sulfonates.-= 01%.8. to-.1,0- carbonatomeand l-clistilleekwaten to*- 250 00;, ,said solution having a:- pH-.-o-.; 1 .7.

ferred image-bearing layer to thewgel blank film. 65

Bath} H had ancheragelg-reatlygsuperior.- to.-Bath Gv. whi1e-Bath -I was i intermediate in. properties:

EXAMELELV.

A front film" element'of the type'describediin; Example IV wasprocessedas'described irr'that 153. example except thatairr place-f; the; geleblanlc':

20;: aeidLZprior. to coating. With two minutecontact time emulsion-transfer. occurred. as. before.

EXAMIELE. VI;

A front" film element of'ithetype 'describedi'in.

251 Example IV was processed"as'described" in' that example except that: place of thef. gelblank there was substitutedqa gele'blanleihaving-o 70. mgz: perkv squares decimeter; gelatin: coated: fromzax. 6% solution of gelatin: containingsap'onimasxat.

wetting agent and adjusted to pH 7.5 with sodium hydroxide prior tocoating': With two minutes contactetime, emulsion-transfer: occurred as before, because the; acid ofthe..w.et-.-film. (A); was sumeientl to overcome-tthe; alkalinity; ofthe gel? 35.3. blank films EXAMPLE A front film element ofthetype .describedyinl Example IV but free from-.the abrasiongel coatl.

of film (A) was processedinliliemanner. with, similar results.

M f font filin element-of "the type clesoribedin Example llfiwas processed as described" in that example except* that in place of the" gel blank a there was sub'stituted a .gelblankhaving 70 mg:

per-*square decimete-r of gelatin coated fromlthel following: solutions 4l60l%..ge1atin 0.801%1'. chromealum. aqueous solution 10% 0.02%" saponin Remainder. water. Adjustedto ,pH .4.7. with .sul

fiiricacidg EXAMELELIXL Aefrontefilm; element otthe :type described. in.

example. except: that in place, of. the. gel-blank theres.waasubstitutedaa; gel-blankthaving '70 mg. pea: sqiuare'jdecimeter, of gelatin coated ifromithee followingtsolution:

4760 721 gelatin 0:23%- -formalln*- (40% formaldehyde) Remainderz-waterr Adjustecl to-pH "l5 with liy drochlorim acid A strippings film and e geleblank film. similar to: tl'i at ofi Example I: werensoaked for 20LLseccnds=.

Ercntaandzrear fiImsaSimiIar: to 'those of; ati'mi inla-itransferbatll' made abyyadmixing;

amplezI. were exposedizasza bipa'clm 'llhesfrontz (A): was the1r:.deve1onedi-,.rinsech .amiaflxezia assinzExampleL: exceptthezffieing timeewas: exetendect:.to;.=20 'llheafihnMAd. wassthem washeiiafiiveemmutesizmdxprompttyrdxied.

equal volumese oi bathsaE and 3 The: gelatin-i surfaces of the soaked films were rolled into"conetactand: stripped apart t afterthe I. manner. dea. scriliediimExample themwashedifiireaminutese in water; to remove-excess ofithe-msulfobenzaldee hyde acetal of polyvinyl alcohol. There was excellent anchorage between the two gelatin surfaces.

The wet film bearing the transferred latent image-bearing layer was then: (1) developed for minutes at 68 F. in a developer made by admixing the following components:

Water (125 F.) cc 500.0 N-p-methylaminophenol sulfate grams 2.5 Sodium sulfite, desiccated do 75.0 Hydroquinone do 3.0 Borax (granular) do 5.0

Add cold water to make 1.0 liter.

(2) Washed in water for a period of one minute. (3) Fixed five minutes at 68 F. in a hardening fixer made by admixing the following components:

Water (125 F.) cc 750.0 Sodium thicsulfate grams 300.0 Sodium sulfite (desiccated) do 11.0 Acetic acid (glacial) cc 17.0 Potassium alum "grams" 10.0

Cold water to make 1.0 liter.

(4) Washed for 30 minutes in water at 60 to 70 F. The anchorage of the transferred emulsion layer to the gelatin blank film was excellent during all stages of the process.

EXAMPLE XI Strips of film similar to that of Example I were soaked for about to seconds in the following transfer solutions at 70 F. and then rolled in contact with gel-blank film of the kind described in Example I.

Bath G of Example III Bath H of Example III Bath I of Example III The films treated in baths H and I had improved anchorage as compared to that treated in bath G. Similar results were obtained by increasing the soaking time of the stripping film to 90 seconds and keeping the gelatin blank film dry until the two films were rolled into contact.

In place of the specific film elements described in the foregoing examples there may be substituted other films of the type described above and those described in the Jennings Patent 2,462,503.

The stripping layers need not be wholly composed of the water-soluble polyvinyl acetals de scribed above which contain a solubilizing --COOZ or SO3Z group. However, such polymers constitute the essential and predominant part of the stripping layers. There may be mixed with such acetals water-soluble or hydrophilic hydroxyl polymers, e. g., polyvinyl alcohol of low. medium, or high viscosity, or partially hydrolyzed vinyl esters. polyvinyl acetate and polyvinyl chloracetate, polyvinyl acetals of formaldehyde, acetaldehyde, benzaldehyde, etc., wherein there are sufficient free hydroxyl groups to confer water-soluble or hydrophilic properties.

In place of the anionic surface-active wetting agents described in the above examples, there may be substituted a large number of other specific wetting agents of this type. Suitable agents include the sodium, potassium, ammonium, triethanolamine, triethylamine, cyclohexylamine, piperidine, and tetraethylammonium salts of decyl, dodecyl, tetradecyl, hexadecyl, octadecyl and oleyl sulfates and sulfonic acids, and mixtures of any two or more of such salts. A good commercial mixture is composed of the sodium salts of the sulfated alcohols obtained by the hydrogenation of coconut oil. Still other useful salts are the water-soluble salts, e. g., the sodium, potassium, and ammonium salts of isopropyl naphthalene sulfonate; the sulfonated esters of unsaturated carboxylic acids, e. g., dioctyl sulfosuccinate; sodium tetralin sulfonate, etc.

The amount of anionic surface active wetting agent used in the treating baths may vary over a fairly broad range and is higher than that used for a wetting eifect. A practical range is 10 to grams per liter of solution.

The sodium dodecyl sulfate used in the foregoing examples was electrolyte-free but contained minor amounts of other sodium n-alkyl sulfates of 10 to 18 carbon atoms, being made by sulfating a fraction of higher alcohols obtained from coconut oil as described above.

The pH of the transfer solutions can readily be regulated by the addition of buffering agents. In addition to those of the examples there may be used sodium hydrogen sulfate, potassium acid phthalate; potassium acid tartrate; acetic acid; mixtures of mineral acids with sodium acetate, trisodium phosphate, sodium citrate, sodium tartrate, or sodium lactate. Additional suitable buffers are described in Britten: Hydrogen Ions, volume I, ed. III, pp. 301-305, D. Van Nostrand, New York, 1943.

In addition to its usefulness in the stripping process described above, it is also applicable to the carbon and Carbro processes of photographic reproduction. Th improved adhesion attained between gelatin layers is of value in all of the well-known stripping processes, e. g., those of Potter U. S. P. 2,126,137, Butement U. S. P. 2,197,994 and Marasco U. S. P. 2,182,814.

The present invention has the advantage that it provides a practical process for improving the anchorage between gelatin layers during a transfer stripping operation. It has the further advantage that it is simple and economical. A further advantage is that it utilizes readily available chemicals. A still further advantage is that the acid solution of anionic surface-active agent tends to harden the transferred emulsion layer making it less susceptible to tearing, abrasion, or deformation during the transfer operations.

In assignees related application Ser. No. 27,607, filed May 17, 1948, now Umberger and Grumbine U. S. Patent No. 2,609,290, there is disclosed and claimed a method of insolubilizing certain stripping layers and transferring the outer gelatin layer utilizing transfer baths of the type disclosed above.

This application is a continuation-in-part of my copending application Ser. No. 27,608, filed May 17, 1948, abandoned November 11, 1950.

As many widely different embodiments of this invention can be made without departing from the spirit and scope thereof, it is to be understood seems-2o rigs-cups:witluamaldehydercontainmgi solubiliz- 5 cing group tta'ken: J'fv-rom mthe .classlaconsisting ziof .-;..-'.CQOZ and :FaSOs'Ziwl-mre izds-az member taken ifrom: 'thezgroup consisting lofhhydrogen and the swateresolubleesaltsforming; metals, whibhaalderihydei-is= otherwise unsubstituted, i130- azgelatini blankt-film', thezstepzwhiclncomprises soakingv'said .::image-bearing.layenimamaqueousisolutiomhavn sanpli? belowci 4.5;;andacontaining'i at :leastaone am .sper liter 2110f :ian nanionic ..:'sui:faces active .-,wetti ng'agennipriomto:ipressingifthezgeiatinzsurfaces inn stransfer icontact eiarld sstripping the imageebearinglilayerf-from: thezo'riginal support.

2. In a process of transferring a gelatin imageb'earring dayerswhichi is adhesively joined to a supportzbyameans iofwaa-water-i-soluble to Waterswellable adhesive taken from the group consistl "pl" Water-soluble cellulose. ether s, .cellulose glycolic acid-and"lts- Water=solub1e alkali: metal, ammoniumandamine saltsfstarch glycojlic; acid and 1' itSWater=SO1ubI8 alkali metal ammonium 25 jandtamine salts, polyvinyl i: alcohol, and tiwaterisoluble macromolecular acetals' of ajliydroxyl j jpolymer 1" havinga; pluralitypfi recurring: :interfrom the group consisting of hydrogen and the:

water-soluble salt-forming metals, which aldehyde is otherwise unsubstituted, to a gelatinblank film, the step which comprises soaking said image-bearing layer in an aqueous solution having a pH of 1.0 to 4.5 and containing at least one gram per liter of a water-soluble salt of an alkyl sulfate of to 18 carbon atoms prior to Dressing the gelatin surfaces in transfer contact and stripping the image-bearing layer from the original support.

3. In a process of transferring a gelatin imagebearing layer which is adhesively joined to a support by means of a water-soluble to waterswellable adhesive taken from the group consisting of Water-soluble cellulose ethers, cellulose glycolic acid and its water-soluble alkali metal, ammonium and amine salts, starch glycolic acid and its water-soluble alkali metal ammonium and amin salts, polyvinyl alcohol, and watersoluble macromolecular acetals of a hydroxyl polymer having a plurality of recurring intralinear CHf-CHOH groups with an aldehyde containing a solubilizing group taken from the class consisting of COOZ and SOsZ where Z is a member taken from the group consisting of hydrogen and the water-soluble salt-forming metals, which aldehyde is otherwise unsubstituted, to a gelatinblank film, the step which comprises soaking said image-bearing layer in an aqueous solution having a pH of 1.0 to 4.5 and containing from 10 to 100 grams per liter of a sodium alkyl sulfate of 10 to 18 carbon atoms prior to pressing the gelatin surfaces in transfer contact and stripping the image-bearing layer from the original support.

4. In a process of transferring a gelatin imagebearing layer which is adhesively joined to a 75 I 10 x'support :by sea zwater soluble macromolecular aacetal ofianhydroxyl polymeniha ing'iazplurality hofrecurring intralinear V m-cmsr lno-n g-roups -with an aldehyde containing-*a sblilbili-zing group I taken 1 from 1 the class consisting of -'CO0Z and SO sZwhere-Z =isa member taken from the group consisting- 0f hydrogem and' the 10 water-soluble salt-forming metals, which== aldehyde' 'is otherwise unsubstituted, to -a gelatinblank film; *the step-which comp'r-ises-soakingsaid image bearingdayer in an'aqueous-solution hav- -ing-a pH-of 1 .0 430 4.5" and' containing from" l0' 'to 1 100- grains-per liter of an anionicr' surfaceac'tive shearing: :layerowhi'ch uis adhesivelynj binediutoi a ssupport iby ,ua aiwatemsoluble :ma'cromolecular aacetaliofzaimydroxyhpolymen'havingaacplurality 'iof reourringrintralinear ---:G,'Hz+fL JHOrH "groups --w'ith ail-aldehyde containing" womanizing group taken from the class' con'si's'ting of ---"COOZ and -SOZ'whereZ is K amember taken from thegroup=-consisting-=of= hydrogenand the water-soluble salt -forming ==metals,--whioh' aideh-yde is otherwise I unsubstituted, *to a g'elati-n- --blank' filrn;= the step whiclrcomprisessoaking-said ==image-beari-ng layerin an aqueoussolution hav- "ing-a pH or 110 "-tO 415: andcoh-taining from l fl to 100' grams perliter of aw'water soluble salt of an alkyl sulfate of 10 to 18 carbon atoms prior to pressing the gelatin surfaces in transfer contact and stripping the image-bearing layer from the original support.

6. In a process of transferring a gelatin imagebearing layer which is adhesively joined to a support by a water-soluble macromolecular acetal of a hydroxyl polymer having a plurality of recurring intralinear CHfl-( JHOH groups with an aldehyde containing a solubilizing group taken from the class consisting of -COOZ and SOsZ Where Z is a member taken from the group consisting of hydrogen and the water-soluble salt-forming metals, which aldehyde is otherwise unsubstituted, to a gelatinblank film, the step which comprises soaking said image-bearing layer in an aqueous solution hav- 5 ing a pH of 1.0 to 4.5 and containing from 10 to 100 grams per liter of a sodium alkyl sulfate of 10 to 18 carbon atoms prior to pressing the gelatin surfaces in transfer contact and stripping the image-bearing layer from the original support.

blank film, the step which comprises soaking said image-bearing layer in an aqueous solution having a pH of 1.0 to 4.5 and containing from 10 to grams per liter of a water-soluble salt of an alkyl sulfate of 10 to 18 carbon atoms prior to pressing the gelatin layers of the two respective films in transfer contact and stripping the imagebearing layer from the original support. e 8. In a process of transferring a gelatin imagebearing layer which is adhesively joined to a support by a water-soluble sodium-o-sulfobenzaldehyde acetal of polyvinyl alcohol to a gelatinblank film, the step which comprises soaking said image-bearing layer in an aqueous solution having a pH of 1.0 to 4.5 and containing from 10 to 100 grams per liter of a water-soluble salt of a sodium alkyl sulfate of 10 to 18 carbon atoms prior to pressing the gelatin layers of the two respective films in transfer contact and stripping the image-bearing layer from the original support.

9. A photographic transfer and developing process which comprises soaking a multilayer film having a gelatin latent-image-bearing layer adhesively joined to another latent-image-bearing layer by means of a water-soluble macromolecular acetal of a hydroxyl polymer having a plurality of recurring intralinear groups with an aldehyde containing a solubilizing group taken from the class consisting of --COOZ and. --S03Z where Z is a member taken from the group consisting of hydrogen and the watersoluble salt-forming metals, which aldehyde is otherwise unsubstituted, to a gelatin-blank film, the step which comprises soaking said film in an aqueous solution having a pH of 1.0 to 4.5 and containing from 10 to 1 grams per liter of an anionic surface active wetting agent, pressing the outer gelatin latent-image-bearing layer into contact with the gelatin surface of a gelatin blank film stripping the outer latent-imagebearing layer from the original multilayer film and developing and fixing the gelatin blank film with its adherent latent-image-bearing layer.

12 10. A photographic transfer and developing process which comprises soaking a multilayer film having a gelatin latent-image-bearing layer adhesively joined to another latent-imagebearing layer by means of a water-soluble sodium-o-sulfobenzaldehyde acetal of polyvinyl alcohol, in an aqueous solution having a pH of 1.0 to 4.5 and containing from 10 to grams per liter of an anionic surface active wetting agent, pressing the outer gelatin latent-image-bearing layer into contact with the gelatin surface of a gelatin-blank film stripping the outer latentimage-bearing layer from the original multilayer film and developing and fixing the gelatin blank film with its adherent latent-image-bearing layer.

ARTHUR WILLIAM GRUMBINE. JACOB QUENTIN UMBERGER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,038,118 MacLaurin Apr. 21, 1936 2,088,405 Cahn July 27, 1937 2,248,213 Beck July 8, 1941 2,266,435 Nadeau Dec. 16, 1941 2,448,552 Schulze Sept. '7, 1948 2,462,503 Jennings Feb. 22, 1949 2,615,807 Umberger Oct. 28, 1952 FOREIGN PATENTS Number Country Date 551,116 Great Britain Feb. 8, 1943 574,138 Great Britain Dec. 21, 1945 489,655 Great Britain Aug. 2, 1948 

1. IN A PROCESS OF TRANSFERRING A GELATIN IMAGEBEARING LAYER WHICH IS ADHESIVELY JOINED TO A SUPPORT BY MEANS OF A WATER-SOLUBLE TO WATERSWELLABLE ADHESIVE TAKEN FROM THE GROUP CONSISTING OF WATER-SOLUBLE CELLULOSE ETHERS, CELLULOSE GLYCOLIC ACID AND ITS WATER-SOLUBLE ALKALI METAL, AMMONIUM AND AMINE SALTS, STARCH GLYCOLIC ACID AND ITS WATER-SOLUBLE ALKALI METAL AMMONIUM AND AMINE SALTS, POLYVINYL ALCOHOL, AND WATERSOLUBLE MACROMOLECULAR ACETALS OF A HYDROXYL POLYMER HAVING A PLURALITY OF RECURRING INTRALINEAR 